A centrifugal fan apparatus is disclosed in the present invention. The characteristics of the centrifugal fan apparatus lies in that the width of airflow channel defined between the rim of the impeller and the inner wall of the housing accommodating the impeller is uniform, and two airflow spaces defined between the axial cross section of the impeller and upper housing and lower housing respectively are not symmetry. Due to these two characteristics, the centrifugal fan apparatus is capable of making larger pressure difference to inducing higher flow rate and reducing noise while the centrifugal fan apparatus is operated. The present invention also provides a dust-collecting module that is formed by adopting the centrifugal fan apparatus with a designed dust-collecting casing, which is capable of being a sucker of a vacuum cleaner to collect dust of the surroundings for the purpose of environment cleaning.